I have hundreds of warnings and I don't know what to do about it. They are all about ZERO STIFFNESS IN DIRECTION__ AT JOINT__ EQN. NO.__ and THERE WERE MORE THAN 12 DOF WITH ZERO STIFFNESS.
VILLA QAHTANI R14.std
In your model you have introduced master slave specifications. All the master nodes are not connected to the structure. The diaphragm you used is in X-Z plane. As a result there is no restraints for those vertical nodes in vertical direction. Due to this reason so much "Zero Stiffness" warnings are shown by the program. If you use a rigid type of diaphragm instead of X-Z , the warnings will not be there.